In this sentence, "Si tu tiens absolument à ce que je te lâche en pleine brousse, je ne vais pas me bagarrer." What purpose does à ce serve? Could it be taken out and only use "que" ?
No, you can't drop the preposition. It would totally change the meaning of the phrase.
tenir à ce que = to insist that / to be keen to tenir que (old-fashioned) = to believe that / to maintain that tenir de qqn que = to have heard from someone that